Many internal combustion engine use a combination of a camshaft, lifter, push rod, and rocker arm to operate the intake and exhaust valves of the engine. Generally, the lifter engages the lobe of the camshaft and reciprocates in a bore in response to camshaft rotation. In turn, the reciprocating movement of the lifter is transferred through the push rod and rocker arm to open and close of the valves. Some lifters may employ rollers at the interface with the cam lobe. In operation, the rollers rotate against the cam lobe thereby minimizing friction between the cam lobe and the lifter. For proper operation, the orientation of the roller lifters must be controlled so as to keep the axis of the roller parallel with the axis of the camshaft. Roller lifters, however, have a tendency to rotate within the lifter bore during engine operation and become misaligned, which may result in damage to the lifter and camshaft. For this reason, engines that employ roller valve lifters typically use some type of alignment device that prevents the roller lifters from rotating within the lifter bore.
Guide plates, such as the plate disclosed in U.S. Pat. No. 6,978,752 to Albertson et al., or inserts/clips, such as the member disclosed in U.S. Pat. No. 5,022,356, have been used in the past as alignment devices. These solutions, however, add additional components to the engine which increase cost and complexity, as well as adding the possibility of inadvertently omitting a component.